There are no existing policy measures for the agriculture sector that aim to reduce emissions of GHGs. Legislation targeting gaseous emissions from agriculture, the Integrated Pollution Prevention and Control ( IPPC) Directive, aims to reduce emissions of gases such as ammonia that impact on air quality.
1. Definition of option, state of deployment
2. Data for 2030
3. Data for 2050
4. Factors influencing deployment, potential, etc.
Ref | Option | Technical measure | State of deployment |
|---|
A1 | Dietary change for livestock | Protein intake reduced to better match animal requirements. Proportion of reduced-fibre concentrate or high-sugar grass in diet increases. | This approach is being encouraged to reduce concentrations of N in livestock manure in order to reduce NO 3 leaching. |
A2 | Reduce livestock numbers in response to CAP reform | Numbers of cattle and sheep are expected to decrease as a result of CAP reform | These reductions are already taking place. |
A3 | Improve fertilizer-N use efficiency | Better matching of application to crop uptake and taking better account of N available from crop residues and organic manure application. | This approach is being encouraged to reduce NO 3 leaching. |
A4 | Rumen manipulation: · ionophores in ruminant diets | The addition of ionophores to ruminant diets to decrease protein degradation in the rumen and also decrease CH 4 output | Future new policy |
A5 | Rumen manipulation:· genetic modification of rumen microflora | Manipulation of rumen digestion to change the composition of the rumen microflora so that methanogenic species are less dominant. | Future new policy |
A6 | Increase livestock productivity per head | Increase the number of lactations by dairy cows so that the number of replacements and their GHG emissions are reduced. | Future new policy |
A7 | Use of nitrification inhibitor with N fertilizers | Nitrification of N fertilizers containing ammonium ( NH4) is a major source of N 2O emissions. The addition of compounds to NH4-based fertilizers which inhibit nitrification can reduce N 2O emissions. | Future new policy |
A8 | Reduce grazing | The IPCC default EF for N deposited during grazing is 2.0% but only 1.0% for manure-N applied to land. On this basis reducing cattle grazing can reduce emissions of N 2O since the excreta that would have been deposited to directly to land will be handled as manure. | Future new policy |
A9 | Change from litter-based farmyard manure ( FYM) to slurry systems | Solid manures contain both aerobic and anaerobic microsites where NH4-N can be nitrified to NO 3, providing a source of N 2O emission by denitrification. Slurry, on the other hand, is anaerobic (until the time it is spread onto land) and there is little or no N 2O emission from slurry-based buildings or slurry stores. | Future new policy |
A10 | Anaerobic digestion | Anaerobic digestion captures CH 4 emissions during manure storage and the gas may be used as a fuel | Future new policy |
A11 | Consume white meat instead of red | Life cycle analyses report pig and poultry products to emit significantly less GHG during their production, per kg of final product, than sheep meat, beef or dairy products, primarily due to the very much smaller emissions of CH 4 from the digestive system. | Future new policy |
A12 | The marginal livestock rearing approach | Resources would only be made available for livestock production once land requirements have been meet to optimize crop production in Scotland, meet feasible biomass targets and maintain or enhance biodiversity. | Future new policy |
A 13 | Adopt a Vegan diet | Human protein requirements can be met without the consumption of livestock products, hence eliminating all GHG from livestock production. Crop land used to produce livestock feeds could be used to produce human food. The greater area of land available could lead to reduced fertilizer-N inputs and less N 2O emission. | Future new policy |
Ref | Option | Core data - 2030 |
|---|
Potential | +/- | Key assumptions | Sub-sector | £/t CO 2eq | +/- | Source / Key assumptions |
|---|
A1 | Dietary change for livestock | 10% of total, both CH 4 and N 2O | | Protein intake reduction would continue, encouragement would be given to increase the proportion of reduced-fibre concentrate or high-sugar grass in diets. | All livestock sub-sectors | | | IGER (2001) [Ref 40] |
A2 | Reduce livestock numbers in response to CAP reform | 19% of total, both CH 4 and N 2O | | Assumes 40% reduction in sheep numbers, 20% in beef and 10% in dairy | Sheep, beef and dairy | 0 | | IGER (2001) [Diff to attribute costs of CAP reform, but can be regarded as zero since changes are taking place] |
A3 | Improve fertilizer-N use efficiency | 1% of total, N 2O only | | Better matching of application to crop uptake and taking better account of N available from crop residues and organic manure application would continue. | All crops and grass | 0 | | IGER (2001) zero cost since should reduce fertilizer use and costs |
A4 | Rumen manipulation: · ionophores in ruminant diets | 5% of total, CH 4 only | | Since effects occur via influence on micro-organisms, the relationships are not simple and other factors are involved. The effectiveness of such measures has yet to be fully demonstrated on commercial farms. | Ruminants only (Dairy, beef and sheep) | | | IGER (2001) |
A5 | Rumen manipulation:· genetic modification of rumen microflora | 5% of total, CH 4 only | | Since effects occur via influence on micro-organisms, the relationships are not simple and other factors are involved. The effectiveness of such measures has yet to be fully demonstrated on commercial farms. | Ruminants only (Dairy, beef and sheep) | | | IGER (2001) |
A6 | Increase livestock productivity per head | 3% of total, both CH 4 and N 2O | | Increase the number of lactations by dairy cows so that the number of replacements is reduced. | Dairy | | | IGER (2001) |
A7 | Use of nitrification inhibitor with N fertilizers | 5% of total, N 2O only | | This approach appears to offer the greatest potential for reducing N 2O emissions from fertilizer-N applications as their use will not lead to the drastic reductions in yield possible under some scenarios. | All crops and grass | | | IGER (2001) |
A8 | Reduce grazing | 35% of total, N 2O only | | This reduction very uncertain | Ruminants only (Dairy, beef and sheep) | | | IGER (2001) |
A9 | Change from farm yard manure ( FYM) to slurry systems | 6% of total, N 2O only | | This reduction also very uncertain | Dairy, beef and pigs | | | IGER (2001) |
A10 | Anaerobic digestion | 3% of total, CH 4 only | | Direct reductions of emissions may be small, but CH 4 generated may be used as a renewable fuel to further reduce GHG emissions | Dairy, beef and pigs | | | IGER (2001) |
A11 | Consume white meat instead of red | 25% of total, both CH 4 and N 2O | | This estimate does not take into account possible increase in tillage land needed to supply cereal feeds. | All livestock sub-sectors | Probably high, investment needed | | Garnett (2007) |
A12 | The marginal livestock rearing approach | 10% of total, both CH 4 and N 2O | | The impacts on GHG emissions from such are complex scenario are difficult to estimate, | All livestock sub-sectors | Probably medium | | Garnett (2007) |
A 13 | Adopt a Vegan diet | 30% of total, both CH 4 and N 2O | | The demand reduction scenario, however, would lead to an absolute (global) reduction in GHG emissions if, and only if, levels of consumption declined to match reduced production. | All livestock sub-sectors, and arable farming | Probably high | | Garnett (2007) |
Ref | Option | Core data - 2050 |
|---|
Potential | +/- | Key assumptions | Sub-sector | £/t CO 2eq | +/- | Source / Key assumptions |
|---|
A1 | Dietary change for livestock | 10% | 100% | Protein intake reduction would continue, encouragement would be given to increase the proportion of reduced-fibre concentrate or high-sugar grass in diets. | All livestock sub-sectors | | | IGER (2001) |
A2 | Reduce livestock numbers in response to CAP reform | 19% | 400% | Assumes 40% reduction in sheep numbers, 20% in beef and 10% in dairy | Sheep, beef and dairy | [Diff to attribute costs of CAP reform] | | IGER (2001) |
A3 | Improve fertilizer-N use efficiency | 1% | 200% | Better matching of application to crop uptake and taking better account of N available from crop residues and organic manure application would continue. | All crops and grass | | | IGER (2001) |
A4 | Rumen manipulation: · ionophores in ruminant diets | 5% | 250% | Since effects occur via influence on micro-organisms, the relationships are not simple and other factors are involved. The effectiveness of such measures has yet to be fully demonstrated on commercial farms. | Ruminants only (Dairy, beef and sheep) | | | IGER (2001) |
A5 | Rumen manipulation:· genetic modification of rumen microflora | 5% | 250% | Since effects occur via influence on micro-organisms, the relationships are not simple and other factors are involved. The effectiveness of such measures has yet to be fully demonstrated on commercial farms. | Ruminants only (Dairy, beef and sheep) | | | IGER (2001) |
A6 | Increase livestock productivity per head | 3% | 50% | Increase the number of lactations by dairy cows so that the number of replacements is reduced. | Dairy | Difficult to cost, probably low | | IGER (2001) |
A7 | Use of nitrification inhibitor with N fertilizers | 5% | 60% | This approach appears to offer the greatest potential for reducing N 2O emissions from fertilizer-N applications as their use will not lead to the drastic reductions in yield possible under some scenarios. | All crops and grass | | | IGER (2001) |
A8 | Reduce grazing | 35% | 100% | This reduction very uncertain | Ruminants only (Dairy, beef and sheep) | | | IGER (2001) |
A9 | Change from farm yard manure ( FYM) to slurry systems | 6% | 100% | This reduction also very uncertain | Dairy, beef and pigs | | | IGER (2001) |
A10 | Anaerobic digestion | 3% | 20% | Direct reductions of emissions may be small, but CH 4 generated may be used as a renewable fuel to further reduce GHG emissions | Dairy, beef and pigs | | | IGER (2001) |
A11 | Consume white meat instead of red | 65% | 20% | This estimate does not take into account possible increase in tillage land needed to supply cereal feeds. | All livestock sub-sectors | Probably high, investment needed | | Garnett (2007) |
A12 | The marginal livestock rearing approach | 25% | 100% | The impacts on GHG emissions from such are complex scenario are difficult to estimate, | All livestock sub-sectors | Probably medium | | Garnett (2007) |
A 13 | Adopt a Vegan diet | 84% | 10% | The demand reduction scenario, however, would lead to an absolute (global) reduction in GHG emissions if, and only if, levels of consumption declined to match reduced production. | All livestock sub-sectors, and arable farming | Probably high | | Garnett (2007) |
Ref | Option | Influencing factors |
|---|
State of technology | Significant other impact | Type | Other issues |
|---|
A1 | Dietary change for livestock | Principles understood, barriers costs and/or changes to farming practice | Would reduce emissions of ammonia to air and nitrate to water | This approach is being encouraged to reduce concentrations of N in livestock manure in order to reduce NO 3 leaching. | |
A2 | Reduce livestock numbers in response to CAP reform | NA | Would reduce emissions of ammonia to air and nitrate to water | These reductions are already taking place. | |
A3 | Improve fertilizer-N use efficiency | Principles understood, being implemented | Would reduce emissions of nitrate to water | This approach is being encouraged to reduce NO 3 leaching. | |
A4 | Rumen manipulation: · ionophores in ruminant diets | Yet to be demonstrated on commercial farms | | Future new policy | |
A5 | Rumen manipulation:· genetic modification of rumen microflora | Yet to be demonstrated on commercial farms | | Future new policy | |
A6 | Increase livestock productivity per head | Principles understood | Would reduce emissions of ammonia to air and nitrate to water | Future new policy | Might seem a backward step |
A7 | Use of nitrification inhibitor with N fertilizers | Effectiveness demonstrated | | Future new policy | Effectiveness would vary according to site and season |
A8 | Reduce grazing | Some farmers adopting this practice | Likely to increase emissions of ammonia but could decrease those of nitrate | Future new policy | |
A9 | Change from farm yard manure ( FYM) to slurry systems | Some farmers are doing this to reduce labour costs | Likely to increase emissions of ammonia but could decrease those of nitrate | Future new policy | May be considered by public to have an adverse impact on animal welfare |
A10 | Anaerobic digestion | Well established, capital cost a barrier | Would further reduce GHG emissions by providing a source of renewable energy (methane) | Future new policy | |
A11 | Consume white meat instead of red | Between 1945 and 2000 this was the trend in meat consumption | Would require conversion of grassland to crop land with releases of CO 2. | Future new policy | |
A12 | The marginal livestock rearing approach | Approach understood | | Future new policy | Might be considered to be at variance with free market |
A 13 | Adopt a Vegan diet | Principles well understood | Would reduce emissions of ammonia to air and nitrate to water | Future new policy | Might be extremely difficult to persuade consumers |